1. Field of the Invention
The present invention relates to an information filtering apparatus and information filtering method for facilitating acquisition of necessary information from a storage using a magnetic, optical medium or the like and an information communication network.
2. Description of the Related Art
With progress of social infrastructure in recent information communications, it is desired greatly that an information filtering apparatus be achieved as a technology of supporting enlarged information communication networks and remarkable increases of an communication amount. As the background thereof, it is considered that the information amount which a person can access is greater than that the person can process. Therefore, the information which the person needs often lies buried in a great amount of information.
As a conventional technology relating to the information filtering apparatus, there is a key word logical expression used in, for example, patent search. That is, patents of several hundreds of thousands to several millions are subjected to filtering with the key word logical expression.
However, some problems have been pointed out in the conventional method using the key word logical expression. First, since it is necessary for a user to set a logical expression for a key word with high accuracy, the user needs to adequately recognize characteristics of a filed data group (for example, under what condition the key word of the data is determined) or a structure of a system (for example, whether or not the key word is the system with thesaurus system) to obtain fine retrieval. Secondly, the result obtained by the information filtering is only appraised as matching with the logical expression for the key word. Such a result only matches with the key word, and sometimes is different from the content that the user requires. Alternately, it is not easy for the user to acquire the information with high priority for the user in descending order of priority from among such many retrieval results.
Based on the forgoing, the inventors of the present invention developed an information filtering apparatus for enabling acquisition of filtered result information which is really necessary to the user with high accuracy. This information filtering apparatus is disclosed in Japanese Unexamined Patent Publication HEI9-288683.
The information filtering apparatus described in the above Japanese Patent Publication is explained with FIG. 1. The information filtering apparatus is provided with information filtering unit 1 which subjects an input item to filtering, learning unit 2 which generates necessary information for the information filtering by learning, and interface unit 3 which indicates the filtered item on a display.
Information filtering unit 1 converts a plurality of key words contained in an item into a vector using a code dictionary stored in code dictionary storage section 4. The information filtering unit 1 further calculates a score using the vector. For the score calculation, the positive metric and negative metric for a key word signal are respectively fetched from positive metric storage section 5 and negative metric storage section 6. The necessity and reliability are calculated from the calculated score and a parameter stored in determination parameter storage section 7.
When the necessity and reliability for the input item are thus obtained, the unread data items stored in unread data storage section 8 are rearranged in order of necessity. Interface unit 3 presents the items in descending order of necessity, while obtaining a user evaluation whether the presented item is necessary or necessary. Learning unit 2 modifies the contents of storage sections 4 to 7 for storing the matrixes for use in the score calculation using the user evaluation and the plurality of key words.
There is however a problem that the information filtering apparatus described above cannot divide items for each field thereof to present when user's interests include a plurality of fields.